With the widespread use of mobile devices, such as mobile phones, personal data assistants, tablet personal computers, etc., consumer demand for access to varied types of data continues to grow at a high rate. These devices are commonly used to transmit, receive, and store text, voice, image and video data. While consumers have come to desire fast access to data, the sheer amount of data required to support many software applications places a premium on data management, both at the client device level and at the network level. This premium limits the effectiveness of software applications such as mapping applications, which typically require comparatively large amounts of network data and a significant amount of memory and processing.
Mapping applications are found in a variety of non-portable computing devices, such as desktop computers, as well as in mobile devices, including car navigation systems, hand-held global positioning system (GPS) units, mobile phones, and portable computers. Mapping applications are among the most frequently used software applications and are considered, by some, necessary for personal safety. Although the underlying digital maps are easy to use from a user's perspective, rendering a digital map image on a display device is a data intensive process.
Geographic maps, for example, begin with a set of raw data corresponding to aerial photographs of the earth having millions of overlaying roadways and related location based information labels. The raw map data is derived from a variety of sources, each source providing different amounts and types of information. Effectively mapping a location or region, locating a driving route between a source and a destination, identifying points of interest, etc. requires substantial amounts of data transfer and data processing. Furthermore, many mapping applications require display of different map data at different zoom levels where the amount of detail and features of that detail changes at each zoom level. For example, at a lowest zoom level, scaled farthest away from a target, the map data may contain the boundaries of continents, oceans, and major landmasses with relatively little detail. At subsequent zoom levels, the map data may identify countries, states, homelands, protectorates and other major geographic regions. While at even further subsequent zoom levels, the map data may contain major roads, cities, towns, until eventually the map data contains a relatively large amount of detail including minor roads, buildings, down to even sidewalks and walk ways depending on the region. Information labels providing links to location based services are often incorporated within the map data at higher zoom levels. The amount of detail is determined by the sources of information used to compile the map data at each zoom level. No matter the zoom level, the amount of data is voluminous and generally too large for storage, in total, on mobile client devices and too large for continuous download over a wireless communication network.
Providing a user with the experience of smooth transitions between map images when using the zoom and pan functions within a map application is challenging. Display generation delay during map image transitions is undesirable.